KiwiRail chief executive Peter Reidy said while it was too early to comment on the "specifics" of this latest incident, they are aware the Ngāruawāhia bridge is a black spot for train accidents.

"Over the last four or five years there have been a significant number of anti-trespass safety measures put in. With the community we've been working with the police, we've put significant fencing and anti-trespass measures in, we've had weekly inspections of the fenced areas, we had these anti-climb measures, specialised fencing to stop people trying to access the bridge. There's been a lot going on.

"We've also been investing with the community to educate schoolchildren on the dangers of jumping from the bridge... we've had over 1000 schoolchildren through that."

But more clearly needs to be done, Mr Reidy told Newshub.

"We've obviously got to do more as a holistic group to make sure we can find a solution to prevent these tragic incidents happening again."

There have reportedly been fewer people jumping off the bridge this summer than in previous years.

The girl's death has been referred to the coroner. Her friends are reportedly being spoken to and supported by the police.

The freight train was heading from Hamilton to Auckland.

"Rail tracks around New Zealand are dangerous," said Mr Reidy.

"People should not play around tracks, should not cross railway tracks. Trains move in some situations quite quickly and it's a dangerous place to play."